LucasArts allows Star Wars mods (provided there are no copyrighted characters), their is a whole license agreement between us and them that was established first with Galactic Conquest for BF1942. As for why they don't hire us up to make the next great Star Wars game, well, you'll have to ask them that one.

There is a lot more that it adds than walkers, Space, for one, wouldn't work out nearly as well. We couldn't have the kit setup we have.. um, the higher geom part limit has helped us in a lot of areas. Can't think of what else off hand.

To post screenshots? Come on by to Forums.fsmod.com we have a whole thread dedicated to posting screenshots, as well as a place to submit shots to be featured on the front page for "Screenshot of the week"